1. Field of the Invention
The present invention relates to energy radiation curable ink having a property to be cured when irradiated with energy radiation such as UV radiation, infrared radiation or the like, and an image recording method and an image recording apparatus for using the energy radiation curable ink and forming an image according to an ink-jet system.
2. Description of Related Art
An ink-jet recording method is an image printing method applicable to an on-demand print with a view to printing a small number of copies. In recent years, attention is paid to the ink-jet recording method, because specific papers are not required for the ink-jet recording method. An energy radiation curable ink jet system of the ink-jet recording method is a printing system for placing energy radiation curable ink having a proper to be cured when irradiated with energy radiation such as UV radiation or the like, on a recording medium, irradiating the energy radiation to the recording medium, and thereby curing the energy radiation curable ink.
A UV ink jet system as a kind of the energy radiation curable ink jet system is a printing system using UV ink having a property to be cured when irradiated with UV radiation as a kind of the energy radiation, as the energy radiation curable ink. According to the UV ink jet system, it is possible to print high-quality images by irradiating UV radiation and controlling a diameter of a dot placed.
In order to control the diameter of the dot placed, it is necessary to cure the UV ink immediately after placed on the recording medium. In order to cure the UV ink rapidly as described above, for example, there is a method that provides a UV light source such as a mercury lamp, a metal halide lamp, or the like, for a carriage holding an ink-jet head for ejecting ink so as to be movable, as disclosed in Japanese Patent Application Publication (Unexamined) No. Tokukai-sho 60-132767, and U.S. Pat. No. 61,459,797. However, according to the method, there is a problem that the weight of the carriage becomes heavy, the acceleration of the carriage is reduced, the efficiency of the image printing operation is lowered, or the whole ink-jet printer is bulky.
Further, a method has been known, the method for irradiating UV radiation from the carriage by using an optical fiber, or introducing UV radiation which is parallel rays with a mirror, as disclosed in Japanese Patent Application Publication (Unexamined) No. Tokukai-sho 60-132767, and U.S. Pat. No. 61,459,797. However, because the optical fiber is not bent very much, it is difficult to apply the optical fiber to the carriage movable. Further, because the UV radiation light source which has been generally applied to the ink-jet printer, is a spot light source, there is a problem that it is difficult to change the UV radiation to the parallel rays.
Furthermore, a recording method such as an external surface drum-scanning system or a line recording system, has been known, the recording method for moving mainly the recording medium, without moving the ink jet head or with moving the ink jet head at low speed. In case of applying the recording method, it is possible to irradiate UV radiation to the UV ink placed on the recording medium rapidly. However, in the case, it is difficult to realize both the small spaced UV radiation light source and the high irradiation of UV radiation to the recording medium. Specially, because it is necessary to irradiate UV radiation to the recording medium for every color of the color print, it is difficult to realize both the small spaced UV radiation light source and the high irradiation of UV radiation. Therefore, in case of irradiating UV radiation having high luminance to the UV ink placed on the recording medium rapidly, it has been necessary to enlarge the ink-jet printer.